Serum Thyrotrophic-receptor Auto Antibodies Levels After ～(131)I Therapy In Graves' Patients And Effect Of Pretreatment With ATD

Objective: there is a transitory increase in levels of thyrotrophic receptors antibodies (TRAb) after radioiodine therapy (¹³¹I) in hyperthyroid Graves disease, Immunosuppressive effects of anti thyroid drugs (ATD) are still a matter of debate. In this study we evaluated the effect of anti thyroid drug pretreatment on the TRAb boost induced by ¹³¹I.Methods: 41 patients were assigned to receive ¹³¹I alone (18 patients) or ¹³¹I plus pretreatment with ATD (23 patients). Serum TRAb levels measured on the day of ¹³¹I dosing (DO), and at 3 and 6 12 months after 131I administration, half a year after follow-up, there is three prognosis: hyperthyroid (Hyper-group); euthyroid(Eu-group); and hypothyroid (Hypo-group).Results:1. Before ¹³¹I treatment, there is no different in TRAb levels between patients treated with ATD and ¹³¹I alone group: 39.95±42.88 U/1, 46.08±51.80 U/1, P>0.05. After ¹³¹I treatment, in patients treated with ATD, TRAb levels increased significantly from DO to 3rd month 39.95±42.88 U/1, 204.32±134.19 U/1, P<0.05 reaching their highest levels at 3rd months. After this, we observed a progressive decrease at 6th months (81.30±92.07U/l). In patients treated with ¹³¹I alone, TRAb levels increased at 3rd month 117.86±103.36 vs. 46.08±51.80 U/1; P<0.05. And at 6th months compared with DO values 105.30±97.70 vs. 46.08±51.80 U/1; P<0.05. After this, we observed a progressive decrease at 6th months. The course of TRAb levels after ¹³¹I treatment was significantly different between the two groups (P>0.05).2. The course of TRAb levels after ¹³¹I treatment was significantly different in the three different prognosis groups (P<0.05). A higher TRAb level before ¹³¹I treatment was associated with hyperthyroidism after half a year of follow-up.Conclusions: (1 )Radioiodine therapy (¹³¹I) in hyperthyroid Graves' disease followed by a transitory increase in levels of TRAb; (2)ATD pretreatment don't attenuates the ¹³¹I -induced rise in serum TRAb levels. (3) high TRAb levels before ¹³¹I are associated with a relative resistance to therapy; there is no decrease in TRAb levels between the 3rd and the 6th month after ¹³¹I are associated with hypothyroid after half a year of follow-up.